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Groups > comp.lang.forth > #25290

Re: LOCALS| and {:

Date 2013-08-18 20:10 +0100
Subject Re: LOCALS| and {:
From Ian van Breda <igvb@btopenworld.com>
Newsgroups comp.lang.forth
Message-ID <CE36DA9A.39D8%igvb@btopenworld.com> (permalink)
References <CE33C486.3991%igvb@btopenworld.com> <520f3862.195907194@news.demon.co.uk>

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Stephen Pelc wrote on 17/08/2013 09:51:
> 
> The notation is nearly 30 years old now. Informed rumour tells
> me that it was originally designed by Don Colbourn. When I
> measured the use of LOCALS| ... | and { ... } in systems that
> have both, the brace notation was used far more than than
> LOCALS|.
> 
> I suspect that the popularity is caused by the brace notation
> looking like a stack comment. The extra features are nice too.
> 

When the ANS Standard was published I immediately realised that LOCALS| made
a big difference to the way in which Forth was coded, especially in limiting
the sometimes complex stack operations that can occur.  This does not get
rid on the stack operations completely but are rather simpler to handle.
However, the main advantage is in the use of named arguments.  Indeed, my
parser would have been, I feel, impossible without LOCALS| - there are 160
LOCALS| lists in the parser code.

LOCALS| and {: are pretty similar.  It is just a matter of whether you work
from the top of the stack down (LOCALS|) or work up from a definite point in
the stack upwards ( {: ).  This is a classic problem with stacks.  See for
example GET-ORDER, do be put the first wid or last on the stack?  Obviously,
I disagree with Hugh Aguilar that LOCALS| was 'total screwed up'.

The logic of my suggestion is, firstly, that ANS included LOCALS| but not
{: and works perfectly well, leaving aside the question of the stack order,
which is a minor matter.  Secondly, it is very easy to implement 'val's in
LOCALS|.  Thirdly, the 'val's are faster than the 'arg's taken off the
stack.  And, fourthly, this makes the two locals methods closely equivalent.

It is important, though, that the LOCALS|/{: should cover more that one line
of source text, to allow named variables that are easy to read later.

Ian
 

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Thread

LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-16 11:59 +0100
  Re: LOCALS| and {: "Alex McDonald" <blog@rivadpm.com> - 2013-08-16 12:31 +0100
  Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-16 13:31 +0000
  Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-16 21:50 +0200
  Re: LOCALS| and {: stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-17 08:51 +0000
    Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-18 20:10 +0100
      Re: LOCALS| and {: Coos Haak <chforth@hccnet.nl> - 2013-08-18 23:32 +0200
      Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-18 15:47 -0700
        Re: LOCALS| and {: "Alex McDonald" <blog@rivadpm.com> - 2013-08-19 15:10 +0100
      Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-19 09:46 +0000
        Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-22 20:15 +0100
      Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-19 07:17 -0500
        Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-19 14:18 +0000
          Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-19 10:25 -0500
            Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-19 15:39 +0000
              Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-19 11:26 -0500
            Re: LOCALS| and {: stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-20 11:25 +0000
              Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-20 10:05 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-21 14:38 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-21 11:48 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-21 16:50 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-21 12:18 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-22 12:33 +0000
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-22 15:26 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-22 12:25 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-23 02:24 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 03:12 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-24 01:22 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 02:56 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-23 01:49 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 03:52 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-23 08:10 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 13:00 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-23 13:46 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 03:01 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-24 03:24 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 12:51 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-25 11:44 -0700
                Re: LOCALS| and {: David Thompson <dave.thompson2@verizon.net> - 2013-08-28 22:27 -0400
                Re: LOCALS| and {: David Thompson <dave.thompson2@verizon.net> - 2013-08-28 22:27 -0400
                Re: LOCALS| and {: "WJ" <w_a_x_man@yahoo.com> - 2013-08-30 02:42 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-22 12:24 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-23 11:50 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 08:13 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-23 13:55 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 13:05 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-24 10:36 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 13:05 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-24 22:44 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-25 04:29 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-25 20:15 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-25 15:51 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-25 23:27 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-26 03:19 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-26 20:38 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-27 11:52 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-28 03:52 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-28 11:55 -0500
                Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-26 11:36 +0000
                Re: LOCALS| and {: David Thompson <dave.thompson2@verizon.net> - 2013-08-28 22:27 -0400
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-21 10:36 -0700
                Re: LOCALS| and {: stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-21 17:22 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-21 12:34 -0500
                Re: LOCALS| and {: mhx@iae.nl - 2013-08-21 23:05 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-22 03:15 -0500
                Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-22 14:49 -0700
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-23 02:07 +0200
                Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-26 20:51 -0700
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-27 15:55 +0200
                Re: LOCALS| and {: mhx@iae.nl - 2013-08-27 10:22 -0700
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-27 17:33 +0000
                Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-27 23:02 +0000
                Re: LOCALS| and {: mhx@iae.nl - 2013-08-27 22:02 -0700
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-27 11:08 -0700
                Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-27 21:16 -0700
                Re: LOCALS| and {: "WJ" <w_a_x_man@yahoo.com> - 2013-08-30 02:56 +0000
              Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-20 20:10 +0000
          Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-20 01:49 +0000
            Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-20 07:14 +0000
        Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-21 10:28 +0100
    Re: LOCALS| and {: "Elizabeth D. Rather" <erather@forth.com> - 2013-08-18 10:04 -1000
      Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-19 20:08 +0100
        Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-20 01:54 +0000
    Re: LOCALS| and {: Mark Wills <markrobertwills@yahoo.co.uk> - 2013-08-20 02:19 -0700
      Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-20 04:37 -0500
  Re: LOCALS| and {: Coos Haak <chforth@hccnet.nl> - 2013-08-17 13:58 +0200
  Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-17 18:49 -0700
  Re: LOCALS| and {: "Ed" <invalid@invalid.com> - 2013-08-23 17:37 +1000

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